JP4351365B2 - Butt welding method for aluminum alloy round bar - Google Patents

Description

図１に示すように、第１の把持体１２により第１の丸棒材１４の先端部をクランプするとともに、第１の電極１７を丸棒材１４に電気的に接続する。加圧装置１６の加圧状態を解除した状態で、第２の把持体１３により第２の丸棒材１５の中間部を把持し、第２の電極１８を丸棒材１５に電気的に接続する。
【００２７】
次に、高電圧印加装置１９を起動する前に加圧装置１６を作動し、所定の初期加圧力で第１の丸棒材１４の先端面１４ａに対し第２の丸棒材１５の先端面１５ａを押圧する。
【００２８】
図３は初期加圧力、二次加圧力、充電電圧、溶接電流及び保持時間等の相関関係を示す。前記通電前の初期加圧により両丸棒材１４，１５の接触抵抗の分布が均一化し、良好な溶接が可能となる。この初期加圧時間は両丸棒材１４，１５が確実に圧接されるのに十分な時間に設定され、本実施形態においては、両丸棒材１４，１５の直径が３ｍｍφ〜８ｍｍφのいずれの場合も１０／６０秒かそれ以上に設定されている。
【００２９】
次に、初期加圧時間が経過した後、両丸棒材１４，１５に二次加圧力（表１の二次加圧力参照）を発生させて加圧状態を保持しながら高電圧印加装置１９を起動し、表１に示す所定の充電電圧を第１の電極１７及び第２の電極１８を介して両丸棒材１４，１５に印加する。この電圧印加により表１に示す所定の溶接電流が両丸棒材１４，１５の押圧接触面に流れる。これにより接触界面はジュール熱により直ちに溶融軟化し、両接触面が互いに融合接合される。
【００３０】
表１に示すように、本実施形態において、溶接電流の大きさは丸棒材１４，１５の直径が例えば４ｍｍφの場合、１４．６ｋＡ、５ｍｍの場合２０．０ｋＡに設定されている。各場合における溶接電流はそれぞれ±２．０ｋＡの範囲において変更可能である。溶接電流が許容範囲を越える場合、溶融部が過剰に大きくなり、溶けたアルミニウム合金が丸棒材１４，１５の外周面に大きく膨らむおそれがある。又、溶接電流が許容範囲未満の場合、接触部位が十分に発熱せず、溶接不良となるおそれがある。これらは、両丸棒材１４，１５の接触部位における発熱量が、電流の２乗に比例することに起因する。なお、前記電極１７, １８は内部に冷却水が循環され、この冷却水により通電時の電極１７, １８が冷却される。
【００３１】
所定の通電時間経過後、両電極１７, １８間の電圧印加を停止して溶接電流を遮断する。表１に示すように、本実施形態において、溶接電流の通電時間は丸棒材１４，１５の直径が３ｍｍ〜８ｍｍのいずれの場合も（４２±３）／６０秒に設定されている。
【００３２】
前記二次加圧力を付与する時間は通電時間〔（４２±３ ）／６０〕よりも長く、両丸棒材１４，１５の直径が３ｍｍφ〜８ｍｍφのいずれの場合も（４６〜６０）／６０秒に設定されている。接合部が所定温度以下に冷却されると、溶融部は凝固され、両丸棒材１４，１５は強固に溶接結合される。
【００３３】
そして、溶接電流を遮断した後、所定の加圧保持時間が経過するまで両丸棒材１４，１５の加圧状態を保持する。両丸棒材１４，１５の溶融部は、通電時間が１秒に満たない短時間であること、及び水冷式の電極１７, １８の冷却作用により、加圧保持時間内に両丸棒材１４，１５の表面に拡大することなく凝固する。そして、所定の加圧保持時間が経過した後、両丸棒材１４，１５への加圧を解除する。すると、両丸棒材１４，１５は十分な溶接強度にて溶接される。
【００３４】
本実施形態において、溶接電流を遮断した後の加圧保持時間は、両丸棒材１４，１５の直径が３ｍｍ〜８ｍｍのいずれの場合も４／６０秒に設定されている。
以上で、両丸棒材１４，１５の直線状（Ｉ）バット溶接による接合が完了となる。
【００３５】
従って、本実施形態によれば、以下のような効果を得ることができる。
（１） ＪＩＳ規格で５０００系（Ａｌ−Ｍｇ系）又は６０００系（Ａｌ−Ｍｇ−Ｓｉ系）のアルミニウム合金製丸棒材１４、１５を直線状に突き合わせ、その直径は３〜８ｍｍの範囲に設定され、各直径の丸棒材の溶接条件を表１のように設定した。このため、接触部位はジュール熱により適度に溶融する。即ち、適度な溶接強度を確保可能な程度の溶融部が形成される。従って、両丸棒材１４，１５をＩバット溶接により強固に接合することができる。
【００３６】
（２） Ｉバット溶接により５０００系又は６０００系のアルミニウム合金製丸棒材同士の接合を可能とした。バット溶接は従来のアルゴンアークスポット溶接による接合の場合に比べて、溶接１点当たりの加工コストが安くなると共に、加工時間が短縮される。従って、溶接箇所の多い商品の製品単価を低減することができる。
【００３７】
次に、図４に基づいて前記両丸棒材１４，１５をＴ字状に突き合わせるＴバット溶接方法について説明する。
図４に示すように、両丸棒材１４，１５をＴ字状に突き合わせるため、第１の把持体１２の構成を変更する。第２の丸棒材１５の先端面１５ａは加工することなく円形平面とする。
【００３８】
この状態で、両丸棒材１４，１５同士をそれぞれの外側から両電極１７, １８により挟持すると共に、両丸棒材１４，１５を互いに近接する方向に加圧する。この溶接条件は、表２のとおりである。
【００３９】
【表２】

本実施形態においても、通電前の初期加圧力を付与する時間は両丸棒材１４，１５の直径が３〜８ｍｍの場合、１０／６０秒かそれ以上に設定されている。
【００４０】
初期加圧時間が経過した後、加圧状態を保持しながら両電極１７, １８間に表２に示す所定の電圧を印加すると、両丸棒材１４，１５の接触部分には溶接電流がほぼ均等に流れる。このため、両丸棒材１４，１５の接触部分には十分なジュール熱が発生する。以下、前述したＩバット溶接方法と同様の作用によりＴバット溶接が完了する。
【００４１】
前記二次加圧力を付与する時間は通電時間（４２／６０秒）よりも長く、両丸棒材１４，１５の直径が３ｍｍφ〜８ｍｍφのいずれの場合も（４６〜６０）／６０秒に設定されている。接合部が所定温度以下に冷却されると、溶融部は凝固され、両丸棒材１４，１５は強固に溶接結合される。
【００４２】
溶接電流を遮断した後、所定の二次加圧力を保持する加圧保持時間が経過するまで両丸棒材１４，１５の加圧状態を保持する。両丸棒材１４，１５の溶融部は、通電時間が１秒に満たない短時間であること、及び水冷式の電極１７, １８の冷却作用により、加圧保持時間内に両丸棒材１４，１５の表面に拡大することなく凝固する。そして、所定の加圧保持時間が経過した後、両丸棒材１４，１５への加圧を解除する。すると、両丸棒材１４，１５は十分な溶接強度にて溶接される。
【００４３】
溶接電流を遮断した後の加圧保持時間は、両丸棒材１４，１５の直径が３ｍｍ〜８ｍｍのいずれの場合も４／６０秒に設定されている。
なお、前記実施形態は以下のように変更して実施してもよい。
【００４４】
・ 図５及び図６に示すように、Ｉバット溶接において、両丸棒材１４，１５の接合部に対し絶縁材料よりなる複数に分割した形状保持筒３１を接近・離隔可能に配設してもよい。すなわち、第１の把持体１２を半円筒状の把持片１２ａ，１２ｂに二分割し、両把持片１２ａ，１２ｂに形状保持半円筒３１ａ，３１ｂを連結する。そして、第１の丸棒材１４の先端面１４ａに対し第２の丸棒材１５の先端面１５ａを接触する工程で形状保持筒３１の先端テーパ面３１ｃに第２の丸棒材１５の先端部を案内させつつ形状保持筒３１内に導き、第１の丸棒材１４、第２の丸棒材１５の突き合わせ部を覆う。
【００４５】
この別例では、両丸棒材１４，１５の突き合わせ部の外方への膨らみを防止して溶接終了後の接合部のバリ取り作業や外径を調整する切削作業を不要にすることができる。
【００４６】
・ 図５、６に示す実施形態において、前記棒材１４、１５と形状保持筒３１の内周面との間に所定の隙間を設け、溶接作業中に前記突き合わせ部が膨張して前記隙間に充填されるようにしてもよい。この場合には、接合部の径が大きくなるので、接合強度を向上することができる。
【００４７】
・ 図１に示す実施形態において、第１の把持体１２に対し第１の電極１７の機能を兼用させ、第２の把持体１３に対し第２の電極１８の機能を兼用させるように構成してもよい。
【００４８】
・ バット溶接機に代えて交流抵抗溶接機にバット溶接用電極アダプタを装着してバット溶接を行うようにしてもよい。
・ バット溶接機に代えてコンデンサ式スポット溶接機を用いてもよい。
（定義） この明細書では丸棒材は、三角棒材、四角棒材あるいは五角棒材等を総称して意味し、これらを丸棒材の横断面積に置き換えて溶接条件を設定するものとする。
【００５０】
【発明の効果】
請求項１〜７に記載の発明によれば、ＪＩＳ規格で５０００系又は６０００系の両アルミニウム合金製丸棒材の接触部位における電流密度が適正となり、アルミニウム合金製丸棒材を強固に効率良く接合することができる。
【図面の簡単な説明】
【図１】 この発明のバット溶接方法に用いる溶接装置の非溶接状態の正面図。
【図２】 同じくバット溶接装置の溶接状態の正面図。
【図３】 時間と加圧力、充電電圧及び溶接電流の関係を示すグラフ。
【図４】 Ｔバット溶接の棒材の把持装置を示す正面図。
【図５】 バット溶接装置の別例を示す部分断面図。
【図６】 図５の形状保持筒の横断面図。
【符号の説明】
１６…加圧装置、３１…形状保持筒。[0001]
BACKGROUND OF THE INVENTION
The present invention energizes a state in which both aluminum alloy round bars made in contact with each other are sandwiched between opposing electrodes, and uses the Joule heat generated by this welding current to join both aluminum alloys round bars. It is about the method.
[0002]
[Prior art]
In general, butt welding is the earliest of resistance welding, and when two materials to be welded having the same cross section are pressed against each other and energized, resistance heating (joule heat) is generated on the joint surface, and the temperature rises. When it reaches an appropriate temperature, it is pressed strongly and pressed to join both workpieces. Both welded materials are joined by solidifying the joint.
[0003]
Butt welding is mainly performed on mild steel, but is also applied to copper and aluminum alloys. As conventional butt welding methods for aluminum alloys, a DC butt welding method for aluminum alloys disclosed in Japanese Patent Laid-Open No. 4-365311, a DC butt welding method for aluminum alloy plates disclosed in Japanese Patent Laid-Open No. 7-1151, and There is an upset butt welding method of aluminum alloy shown in Japanese Patent Laid-Open No. 6-328262, and a DC-butt welding method of aluminum alloy for wheels shown in Japanese Patent Laid-Open No. 6-142938.
[0004]
However, since all of the above butt welding methods are intended for plate-like aluminum alloy workpieces, no appropriate butt welding conditions for aluminum alloy round bars have been disclosed.
[0005]
Further, as a first conventional example regarding butt welding of a round bar made of an aluminum alloy, there is "Chain-ring welding method" in Japanese Patent Application Laid-Open No. 60-72686, and as a second conventional example, Japanese Patent Application Laid-Open No. 57-187181. “Materials to be welded for heating and pressure welding” have been proposed.
[0006]
[Problems to be solved by the invention]
The welding conditions of the butt welding method disclosed in the first conventional example “chain ring welding method” are as follows. For aluminum having a wire chain diameter of 6 mm, the primary current for preheating heating is 800 A, and the secondary current is The final energization is 900 A, and the respective waiting times are 0.5 seconds, 0.05 seconds, and 0.6 seconds.
[0007]
However, although it is possible to weld a very small amount of aluminum alloy under the above welding conditions, it has been found that other joint strengths are not sufficient. That is, for example, welding of a 5000 series (Al-Mg series) or 6000 series (Al-MG-Si series) aluminum alloy rod is very high in comparison with other metals such as mild steel. There was a problem that could not be done.
[0008]
In addition, the butt welding method disclosed in the second conventional example “material to be welded for heating and pressure welding” is such that the outer periphery of the butt end surface of both aluminum alloy round bars is tapered to obtain an area of the pressure welding surface. It is said that aluminum can be heated and pressed in a small current region with good stability.
[0009]
However, the butt welding method described above has a problem in that the work cost increases because it is necessary to process the butted surfaces of the round bars in the pre-process of the welding operation.
[0010]
Furthermore, the publication of the second conventional example discloses a conventional butt welding method according to the invention of this publication, and does not process the butted end face of the round bar. And when aluminum, copper, a copper alloy, etc. with low specific resistance have a larger cross-sectional area of junction area, it is described that a higher current density is needed. However, in this butt welding, the specific material and welding conditions of both bars are not specified.
[0011]
As described above, the techniques related to the butt welding method for 5000 series and 6000 series aluminum alloy round bars have relatively few examples and are generally not implemented as being suitable for butt welding.
[0012]
Therefore, when welding an aluminum alloy round bar, argon arc spot welding that does not use Joule heat generated on the contact surface of the aluminum alloy round bar has been widely used. However, this argon arc spot welding requires a longer work time and a higher cost per welding point than butt welding. For this reason, a product unit price tends to increase especially for a product with many welds.
[0013]
The present invention has been made to solve the above-mentioned problems, and the object thereof is an aluminum alloy round bar capable of firmly joining 5000 series or 6000 series aluminum alloy round bars according to JIS standards. An object of the present invention is to provide a butt welding method for a material.
[0014]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, the invention described in claim 1 is characterized in that aluminum alloy round bars (14, 15) are butted linearly or in a T shape, and both round bars (14, 15) are added. In the butt welding method of aluminum alloy round bars that are energized while being pressurized with a pressure device and join the round bars (14, 15) using Joule heat generated by the welding current, the round bars ( 14 and 15) are 5000 series (Al-Mg series) or 6000 series (Al-Mg-Si series) according to JIS standards, and the diameter of both round bars (14, 15) is in the range of 3 to 8 mm. The gist is that energization is performed for a predetermined time at a current density of 859 to 1320 A / square millimeter using a charging voltage of 185 to 1322 V by a capacitor as a butt welding condition.
[0015]
The invention according to claim 2 is the invention according to claim 1, wherein the joining form of the both round bars is I-butt welding in which a straight shape is abutted, and the diameter dimension is 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm. At least the welding current among the initial pressing force, the secondary pressing force, the charging voltage, the welding current, and the energizing time, which are welding conditions of the different round bar materials, was set to the numerical values in Table 1 shown in the section of the embodiment of the invention. This is the gist.
[0016]
The invention according to claim 3 is the invention according to claim 1, wherein the joining form of the both round bars is T-butt welding that is butted in a T shape, and the diameter dimension is 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, At least the welding current among the initial welding pressure, the secondary welding pressure, the charging voltage, the welding current, and the energization time, which are welding conditions for each of the 8 mm different round bars, is set to the numerical values in Table 2 shown in the section of the embodiment of the invention. The summary is as follows.
[0017]
According to a fourth aspect of the present invention, in any one of the first to third aspects, the material of the both aluminum alloy round bars (14, 15) is A5056, A5052, A5082, A5182, A6009 according to JIS standards. , A6010, A6063 are the same as or different from each other.
[0018]
The invention according to claim 5 is carried out by covering the butted portion from the outer peripheral side with a shape-retaining cylinder in the case of I-butt welding of the both aluminum alloy round bars (14, 15). It is a summary.
[0019]
A sixth aspect of the present invention is summarized in that, in the fifth aspect, the shape retaining cylinder is separably assembled into a plurality of segments (31a, 31b) after the welding operation is completed.
[0020]
According to a seventh aspect of the present invention, in the fifth or sixth aspect, a predetermined gap is provided between the bar (14, 15) and the inner peripheral surface of the shape retaining cylinder, and the butting is performed during a welding operation. The gist is that the portion expands and fills the gap.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
The butt welder will be described with reference to the schematic diagram of FIG. 1. First and second grips 12 and 13 are mounted on the upper surface of the bed 11, and first and second round bars 14 and 15 made of aluminum alloy. Are held in a horizontal state and are opposed to each other so that both bars 14 and 15 are located on the same axis. The first gripping body 12 grips the first round bar 14 at a predetermined position, the second gripping body 13 grips the second round bar 15, and a fluid pressure pressurizing device 16. Thus, the tip surface 15a of the second round bar 15 can be moved in the axial direction thereof and pressed against the tip surface 14a of the first round bar 14.
[0022]
A first electrode 17 and a second electrode 18 are disposed in the vicinity of the first grip body 12 and the second grip body 13, and a high voltage is applied to both the electrodes 17 and 18 from a high voltage application device 19. Is applied. The high voltage application device 19 includes a capacitor 20, and applies a voltage charged thereto to the first electrode 17 and the second electrode 18 to energize the first and second round bars 14, 15. We are trying to weld.
[0023]
The material of the round bars 14 and 15 is an Al—Mg based aluminum non-heat treated alloy (A5052P, A5056P, A5082P, A5182P alloy, etc.) known as JIS standard 5000 series alloy. Moreover, it is good also as an Al-Mg-Si type aluminum heat treatment alloy (A6009P, A6010P, A6063P) known as a JIS standard 6000 series alloy.
[0024]
The diameters of the circular cross sections of the first and second round bars 14 and 15 are set in the range of 3 to 8 mm.
Next, a method of joining the round bars 14 and 15 in a straight line, that is, in an I shape using a butt welder (I butt welding) and a method of joining in a T shape (T butt welding) will be sequentially described. .
[0025]
Table 1 shows various conditions of the I-butt welding method.
[0026]
[Table 1]

As shown in FIG. 1, the tip end portion of the first round bar 14 is clamped by the first grip body 12, and the first electrode 17 is electrically connected to the round bar 14. With the pressurization state of the pressurizing device 16 released, the second gripping body 13 grips the middle part of the second round bar 15 and electrically connects the second electrode 18 to the round bar 15. To do.
[0027]
Next, before the high voltage applying device 19 is started, the pressurizing device 16 is operated, and the front end surface of the second round bar 15 with respect to the front end surface 14a of the first round bar 14 with a predetermined initial pressure. Press 15a.
[0028]
FIG. 3 shows the correlation between the initial pressure, the secondary pressure, the charging voltage, the welding current, the holding time, and the like. By the initial pressurization before the energization, the distribution of contact resistance between the round bars 14 and 15 becomes uniform, and good welding becomes possible. This initial pressurizing time is set to a time sufficient to ensure that the round bars 14 and 15 are pressed against each other. In this embodiment, the diameter of the round bars 14 and 15 is any of 3 mmφ to 8 mmφ. In this case, it is set to 10/60 seconds or more.
[0029]
Next, after the initial pressurization time has elapsed, a secondary pressure (see the secondary pressure in Table 1) is generated on the round bars 14 and 15 to maintain the pressure state, and the high voltage application device 19 is maintained. And a predetermined charging voltage shown in Table 1 is applied to both the round bars 14 and 15 via the first electrode 17 and the second electrode 18. By applying this voltage, a predetermined welding current shown in Table 1 flows on the pressing contact surfaces of both round bars 14 and 15. As a result, the contact interface is immediately melted and softened by Joule heat, and both contact surfaces are fused and joined together.
[0030]
As shown in Table 1, in this embodiment, the magnitude of the welding current is set to 20.0 kA when the diameter of the round bars 14 and 15 is, for example, 4 mmφ, 14.6 kA, and 5 mm. The welding current in each case can be changed within a range of ± 2.0 kA. When the welding current exceeds the allowable range, the melted portion becomes excessively large and the molten aluminum alloy may swell greatly on the outer peripheral surfaces of the round bars 14 and 15. In addition, when the welding current is less than the allowable range, the contact portion does not sufficiently generate heat, which may result in poor welding. These are due to the fact that the amount of heat generated at the contact portion of both round bars 14 and 15 is proportional to the square of the current. Note that cooling water is circulated in the electrodes 17 and 18, and the electrodes 17 and 18 when energized are cooled by the cooling water.
[0031]
After a predetermined energization time has elapsed, the voltage application between both electrodes 17 and 18 is stopped to interrupt the welding current. As shown in Table 1, in this embodiment, the energization time of the welding current is set to ( 4 2 ± 3 ) / 60 seconds in any case where the diameters of the round bars 14 and 15 are 3 mm to 8 mm.
[0032]
The time during which the secondary pressure is applied is longer than the energization time [ (4 2 ± 3) / 60] , and the diameters of both round bars 14 and 15 are 3 mmφ to 8 mmφ ( 46-60 ) / It is set to 60 seconds . When the joint is cooled to a predetermined temperature or lower, the melted portion is solidified, and both the round bars 14 and 15 are firmly joined by welding.
[0033]
And after interrupting welding current, the pressurization state of both the round bars 14 and 15 is hold | maintained until predetermined pressurization holding time passes. The melted portion of both the round bars 14 and 15 has both the round bars 14 within the pressurization holding time due to the short time of energization time of less than 1 second and the cooling action of the water-cooled electrodes 17 and 18. , 15 solidify without expanding. Then, after a predetermined pressurization holding time has elapsed, the pressurization to both the round bars 14 and 15 is released. Then, both the round bars 14 and 15 are welded with sufficient welding strength.
[0034]
In this embodiment, the pressurization holding time after cutting off the welding current is set to 4/60 seconds in both cases where the diameters of the round bars 14 and 15 are 3 mm to 8 mm.
This completes the joining of the round bars 14 and 15 by linear (I) butt welding.
[0035]
Therefore, according to the present embodiment, the following effects can be obtained.
(1) JIS standard 5000 (Al-Mg) or 6000 (Al-Mg-Si) aluminum alloy round bars 14 and 15 are linearly abutted and the diameter is in the range of 3 to 8 mm. Table 1 shows the welding conditions for the round bars of each diameter. For this reason, the contact portion is appropriately melted by Joule heat. That is, a melted portion is formed to an extent that can ensure an appropriate welding strength. Therefore, both the round bars 14 and 15 can be firmly joined by I-butt welding.
[0036]
(2) It was made possible to join 5000 series or 6000 series aluminum alloy round bars by I-butt welding. In the butt welding, the processing cost per welding point is reduced and the processing time is shortened as compared with the case of joining by conventional argon arc spot welding. Therefore, it is possible to reduce the product unit price of a product with many welds.
[0037]
Next, a T-butt welding method for abutting the round bars 14 and 15 in a T shape will be described with reference to FIG.
As shown in FIG. 4, the configuration of the first holding body 12 is changed in order to abut the both round bars 14 and 15 in a T shape. The tip surface 15a of the second round bar 15 is a circular plane without being processed.
[0038]
In this state, both the round bars 14 and 15 are sandwiched between the electrodes 17 and 18 from the outside, and both the round bars 14 and 15 are pressed in a direction close to each other. The welding conditions are as shown in Table 2.
[0039]
[Table 2]

Also in the present embodiment, the time for applying the initial pressure before energization is set to 10/60 seconds or more when the diameters of the round bars 14 and 15 are 3 to 8 mm.
[0040]
When the predetermined voltage shown in Table 2 is applied between the electrodes 17 and 18 while the pressurization state is maintained after the initial pressurizing time has elapsed, the welding current is almost at the contact portion of both the round bars 14 and 15. It flows evenly. For this reason, sufficient Joule heat is generated at the contact portions of the round bars 14 and 15. Thereafter, the T-butt welding is completed by the same action as the above-described I-butt welding method.
[0041]
The time during which the secondary pressure is applied is longer than the energization time (42/60 seconds ), and the diameter of both round bars 14 and 15 is set to ( 46-60 ) / 60 seconds in any case of 3 mmφ to 8 mmφ. Has been. When the joint is cooled to a predetermined temperature or lower, the melted portion is solidified, and both the round bars 14 and 15 are firmly joined by welding.
[0042]
After the welding current is cut off, the pressurized state of both round bars 14 and 15 is maintained until the pressurization holding time for holding a predetermined secondary pressurizing force elapses. The melted portion of both the round bars 14 and 15 has both the round bars 14 within the pressurization holding time due to the short time of energization time of less than 1 second and the cooling action of the water-cooled electrodes 17 and 18. , 15 solidify without expanding. Then, after a predetermined pressurization holding time has elapsed, the pressurization to both the round bars 14 and 15 is released. Then, both the round bars 14 and 15 are welded with sufficient welding strength.
[0043]
The pressurization holding time after cutting off the welding current is set to 4/60 seconds in both cases where the diameters of the round bars 14 and 15 are 3 mm to 8 mm.
In addition, you may implement the said embodiment as follows.
[0044]
As shown in FIGS. 5 and 6, in I-butt welding, a plurality of shape holding cylinders 31 made of an insulating material are arranged so as to be able to approach and separate from the joint portion of both round bars 14, 15. Also good. That is, the first holding body 12 is divided into two half-cylindrical holding pieces 12a and 12b, and the shape-holding half-cylinders 31a and 31b are connected to both holding pieces 12a and 12b. Then, the tip of the second round bar 15 is brought into contact with the tip tapered surface 31c of the shape retaining cylinder 31 in the step of contacting the tip face 15a of the second round bar 15 with the tip face 14a of the first round bar 14. It guide | induces in the shape holding cylinder 31, guiding a part, and covers the butt | matching part of the 1st round bar material 14 and the 2nd round bar material 15. FIG.
[0045]
In this other example, it is possible to prevent the butt portion of both round bars 14 and 15 from bulging outward and to eliminate the deburring operation of the bonded portion after welding and the cutting operation of adjusting the outer diameter. .
[0046]
In the embodiment shown in FIGS. 5 and 6, a predetermined gap is provided between the bar members 14, 15 and the inner peripheral surface of the shape retaining cylinder 31, and the abutting portion expands during the welding operation so that the gap It may be filled. In this case, since the diameter of the joining portion is increased, the joining strength can be improved.
[0047]
In the embodiment shown in FIG. 1, the first holding body 12 is also used as the function of the first electrode 17, and the second holding body 13 is used as the function of the second electrode 18. May be.
[0048]
A butt welding electrode adapter may be attached to an AC resistance welding machine instead of the butt welding machine to perform butt welding.
-A capacitor-type spot welder may be used instead of the butt welder.
(Definition) In this specification, a round bar is a generic term for a triangular bar, a square bar or a pentagonal bar, and the welding conditions are set by replacing these with the cross-sectional area of the round bar. .
[0050]
【The invention's effect】
According to the first to seventh aspects of the present invention, the current density at the contact portion of both the 5000 series and 6000 series aluminum alloy round bars according to JIS standards becomes appropriate, and the aluminum alloy round bars are made strong and efficient. Can be joined.
[Brief description of the drawings]
FIG. 1 is a front view of a welding apparatus used in the butt welding method of the present invention in a non-welded state.
FIG. 2 is a front view of the welding state of the butt welding apparatus.
FIG. 3 is a graph showing the relationship between time, applied pressure, charging voltage, and welding current.
FIG. 4 is a front view showing a bar-holding device for T-butt welding.
FIG. 5 is a partial cross-sectional view showing another example of the butt welding apparatus.
6 is a cross-sectional view of the shape retaining cylinder of FIG.
[Explanation of symbols]
16 ... pressurizing device, 31 ... shape retaining cylinder.

Claims (7)

The aluminum alloy round bars (14, 15) are butted linearly or in a T-shape, and both round bars (14, 15) are energized while being pressurized by the pressurizer (16), and Joule heat is generated by this welding current. In the butt welding method of aluminum alloy round bars that join the round bars (14, 15) using
The material of the round bar (14, 15) is 5000 series (Al-Mg series) or 6000 series (Al-Mg-Si series) according to JIS standard, and the diameter dimension of both round bars (14, 15) is 3. A round bat made of aluminum alloy characterized by being energized for a predetermined time at a current density of 859 to 1320 A / square millimeter using a charging voltage of 185 to 1322 V by a capacitor as a butt welding condition set in a range of ˜8 mm Welding method. In Claim 1, the joining form of the said both round bar materials is I butt welding which is faced | matched linearly, Comprising: Welding conditions of each round bar material from which a diameter dimension differs 3mm, 4mm, 5mm, 6mm, 7mm, 8mm Butt welding of aluminum alloy round bars with at least the welding current set to the numerical values in Table 1 shown in the section of the embodiment of the present invention, initial pressing force, secondary pressing force, charging voltage, welding current and energization time Method. In Claim 1, the joining form of the said both round bar materials is T butt welding by which T shape is faced | matched, Comprising: The welding of each round bar material from which a diameter dimension differs 3mm, 4mm, 5mm, 6mm, 7mm, 8mm. Aluminum alloy round bar bat in which at least the welding current is set to the numerical values in Table 2 shown in the section of the embodiment of the present invention: initial pressing force, secondary pressing force, charging voltage, welding current and energization time Welding method. The material of the aluminum alloy round bars (14, 15) according to any one of claims 1 to 3 is the same as the materials of A5056, A5052, A5082, A5182, A6009, A6010, A6063 according to JIS standards. Or a butt welding method for aluminum alloy round bars made of a combination of different materials. The round bar made of aluminum alloy according to claim 2, wherein the butted portion is covered with a shape-holding cylinder (31) from the outer peripheral side during the I-butt welding of the both round bars made of aluminum alloy (14, 15). Butt welding method of the material. The butt welding method for aluminum alloy round bars according to claim 5, wherein the shape retaining cylinder (31) is separably assembled into a plurality of segments (31a, 31b) after completion of the welding operation. In Claim 5 or 6, a predetermined gap is provided between the bar (14, 15) and the inner peripheral surface of the shape retaining cylinder (31), and the butt portion expands during the welding operation, A butt welding method for aluminum alloy round bars filled in the gaps.

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